Time-dependent investigation of sub-monolayers of Ni on Pd using Positron-annihilation induced Auger Electron Spectroscopy and XPS

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• 作者：Samantha Zimnik ^{samantha.zimnik@frm2.tum.de" class="auth_mail" title="E-mail the corresponding author} ; Christian Piochacz ; Sebastian Vohburger ; Christoph Hugenschmidt
• 关键词：Positron-annihilation induced Auger Electron Spectroscopy (PAES) ; Positron annihilation ; Auger electron spectroscopy (AES) ; XPS ; Nickel ; Palladium
• 刊名：Surface Science
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：643
• 期：Complete
• 页码：178-182
• 全文大小：425 K

文摘

The surface of a polycrystalline Pd-substrate covered with (sub-) monolayers of Ni was investigated with Positron-annihilation induced Auger Electron Spectroscopy (PAES). Comparative studies using conventional AES induced by electrons and X-rays showed the outstanding surface sensitivity of PAES. Time-dependent PAES was performed on a 0.5 ML Ni cover layer on Pd and compared with conventional X-ray induced Photoelectron Spectroscopy (XPS) in order to observe changes in the elemental composition of the surface. The PAES results appear to show a migration of Ni atoms into the Pd substrate, whereas the Ni signal shows a decrease of 12% within 13 h with respect to the initial value.